If you get a leash, spend the couple extra bucks for a retractable one.
I was lucky enough to find one at a local liquidators for three bucks, elliot has a red one, and aerowyn has a blue one (to match their red and blue harnesses, which match their red and blue collars of course
) The ones I have are 25 feet. THe retractable ones also have buttons you can press down and hold, and should have a locking mechanism so you can have the leash at a desireable length. Its alot easier than having a six foot leash you buy at pet smart, because you dont have to trail after your cat, and its alot easier for me because neither of my cats ever want to go the same way, so this way they both have a fifty foot diameter to explore in.
Also for a harness, get one that goes around the neck in a circle, around the behind of the elbows in a circle, and connects the two circles with a line on top and on the chest. I have one that just connects them on the top for my kitten aerowyn, and it is constantly slipping down to the side and is uncomfortable for her.
Train with harnesses and leashes at a young age (or as young as you can manage to fit the harness on anyways) Trying to pull your cat isnt a good idea either.. mostly just carry him/her to the place he/she will be walking around in, and let him/her do what she wants.
You CAN train your cats to walk on a leash though, it just takes a while. Elliot walks good, if I tug him a bit in a direction he will go that way, keeping mostly to the "heel" thing. Aerowyn is just getting the hang of it, and will come running if I tug on the leash a bit, or pull insistantly for her to come
(after giving me a dirty look of course, she comes)
Lots of catnip toys are a good idea
cats love catnip toys. Maybe not for the youngerones though? I read somewhere you arent supposed to give them catnip until they are about 6 months or a year. theres something called Da-Bird you can buy at petsmart, that alot of people here have for their cats... My cats have a wide variety of toys from homemade (poor mutilated stufed animals, which I cut open, pulled otu the stuffing, shoved in catnip, and sewed up again) to store bought (feathery things, soft things, fluffy things) Most cats seem to like the fake mice, you can buy the brightly colored ones for cheap. There are also these rabbit fur balls that they sell at vet's offices that my cats like, and elliot LOVEs those big mice that feel and smell real, with their soft rabbit fur coverings. Feathery toys are favorites also. I have this one thing which is a long yellow stick wtih a suction cup at one end, and the other has a string going down with a rabbit ball on the end that has feathers and a bell on it. Its like taht "da bird" thing I guess.
Something I bought at fleet farm for five bucks is one of those automatic waterers. It's not electric, just one of those ones that you fill the top part, put on the bottom and flip over. The water tray then fills, and the cats can enjoy it when the water gets too low, more water will come out and put air bubbles in the water holder.
Wee, I type too much all the time.
Anyways, hope this helped a bit
oh, and a good place to get cat trees is on Ebay. These people that make them.. called.. amarakat??? I cant remember, but someone made a post about it about a month ago, well they have really good cat trees, some like eight levels, and its only like 20 bucks! I payed 100 for this dinky one at petco! Its just a little house with a pole and a perch at the top :P Definitely look into ebay for a cat tree, it will be sooo much cheaper.